Chronograph-watch.



E. HART.

GHRONOGBAPH WATCH.

urmcnon nun n 25, 1911.

Patented Aug. 1, 1911.

UNITED STATES PATENT OFFICE.

EDWIN HART, OF WATERBURY, CONNECTICUT, ASSIGNOR TO THE NEW ENGLAND WATCH CO., OF WATERBURY, CONNECTICUT, A CORPOBATION.

CHRONOGRAPH-WATCI-.

Speeificaton of Letters Patent.

Patented Awr. 1, 1911.

Application filed May 25, 1911. Serial No. 629290.

T o all whom tt may conccrn:

Be it known that I, EDWIN HART, a citizen of the United States, residing at VVaterbury, in the County of New Haven and State of Connecticut, have invented a new and useful Improvement in Chronograph-XVatches; and I do hereby declare the following, when taken in connection with the accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specifioation, and represent, in

Figure 1 a broken plan view of a stopwatch or chronograph embodying my invention, with the center chronograph -wheel held in its normal or zero position by the coaction of the *fly-back lever with the heartcam. Fig. 2 a corresponding view with the parts shifted for putting the chronograph into action. Fig. 3 an edge view of the watch-movement, looking in the direction of the arrow a, a portion of the three-quarter plate being broken away to show the coiled spring employed for the operation of the push-lever and the hook-pawl. Fig. 4 a broken edge view of the movement, looking in the direction of the arrow b and showing the arrangement of the coiled spring employed for Operating the fiy-back lever. Fig. 5` an edge view of the movement, looking in the direction of the arrow c and showing the arrangement of the coiled spring employed for the operation of the intermediate lever. Fig. 6 a broken sectional view showing the mode of mounting the ratchet-wheel and Castle-wheel upon the three-quarter plate.

My invention relates to an improvement in that class of chronograph or stop-watches in which the chronograph mechanism is for the most part superimposed upon the threequarter plate and cut into and out of action by the longitudinal movement of the winding and setting stem; the object of my present invention being to greatly simplify and 'cheapen the Construction of the chronograph mechanism, as well as to secure greater reliability of performance and an economy ot space, by employing spiral springs instead of fiat springs as heretofore.

With these ends in view my invention consists in a watch having certain details of Construction and combinations of parts as will be hereinatter described and pointed out in the claim.

In carrying out my invention as herein shown, I employ a coiled spring 2 encircling the push-lever stud 3 mounted in the pushlever 4: which swings upon the push-lever screw 5. The said push-lever l: carries a push-lever pin 6 which co-acts with an annular shoulder 7 near the extreme inner end of the winding-and-setting stem S. The said stud 3 reaches upward through a clearance-hole 9 in the three-quarter plate 10 and at its projecting upper end carries a hook pawl 11 which reeeivos the upper end 12 of the spring 2 the lower end 13 of which is entered into the inner end of the said lever 4. The said pawl 11 engages with the teeth of a ratchet-wheel 14 turning upon a stud 15 mounted in the plate 10, the said ratchet wheel 14 and the Castle-wheel 16 secured to it, being held upon the stud by means of a retaining-screw 17 as shown in Fig. 6. The arms of the Castle-wheel 16 co-act with the finger 18 ot an intermediate lever 19 hung upon a stud 20 in the three-quarter plate 10 and operated by a spira] spring 21 encircling the said stud 20 and having one of its ends entered into the said plate 10 and its opposite end entered into the lever 19 which the spring` eXerts a constant eiort to swing inward so as to bring the fine teeth of the intermediate chronograph-wheel, -carried by the lever 22 into engagement with the teeth of the center-chronograph wheel 23 which is mounted upon a shaft 24 carrying at its inner end a heart-cam 25 and provided upon its outer end with a seconds pointer which is not shown. The heart-cam 25 is operated to restore the seconds pointer to its zero position, by means of a fiy-back lever 26 secured to a post 27 having a shank 28 which passes through the three-quarter plate 10 and through the pillar-plate 29 which latter corresponds to the back-plate of an ordinary watch movement. A split collar 30 on the shank 28 holds the same against endwise play. At its outer end the lever 26 has an arm 31 having a finger 32 receiving one end of a coiled spring 33 encircling a screw 3 1 mounted in the three-quarter plate 10, which the opposite end of the spring 33 enters, whereby the spring 33 eXerts a constant etfort to throw the fly-back lever into engagement with the heart-cam 25.

It will be seen froni the foregoing description that the push-lover 4, the intermediate lever 19 and the fiy-back leVer 2 are operated by spiral springs instead of by the flat springs heretofore generally eniployed spiral springs being nore eticient and reliahle, taking up less room and requiring less delicaey of Construction, installation and adjustnent.

I wish to particularly call attention to the fact that the spiral spring 2 not only exerts a constant efi ort to keep the hook-pawl ll engaged with the teeth ot' the ratchet-wheel lt but also exerts a constant ettort to swing the push-level' l inward. 'When the sten 8 is thrust inward, the shoulder 7 thereof acts upon the pin G to Swing the lever upon the stud 3. Now as the nose ot' the hook-pawl 11 is at this tine engaged with a tooth of the ratchet-wheel lat, the eitect will he to turn the saine :ti-oni right to left in which inovenent the pawl will he swung outward with the eflect of coiling the spring 2 and hence increasing its tension. The efiort ot' the spring 2 to uncoil swings the lever i inward and causes the hook of its pawl 11 to engage with another tooth of the wheel 14. It thus appears that the single spring 2 suffices both tor the operation ot the said level' a and tor the hook-pawl ll. The arms of the Castle-wheel 16 co-act as usual with the finger 18 of the intermediate level' 19 for the oseillation thereof, as well as with the cani 35 of the fly-back leVer 26 for the oscillation 'hereot The Castle-wheel is held in its several positions by a spring-arni 34.

hat l particularly wish to einphasize is that I have cheapened the Construction and increased the reliability of stop or chronograph watches as well as secured econony of space by using spiral in place oi" flat springs, and in particular by using the single spiral spring 2 for the operation ot' the push-lever land hook pawl ll.

In a chronograph or stop-watch, the conibination with a pivotal push-level', of a winding-and-setting stein co-acting with one end of the said lever, a stud n'ounted .in the other end of the lever, a hook pawl carried hy the said stud, a spiral spring encircling the said stud and having one end entered into the said leve and the opposite end entered into the said pawl wherehy the said spring is placed under tension hy the operation of the said lever by the said ste, a ratchet-wheel and a Castle-wheel revolving together` the toriner co-acting with the hook pawl, a fly-hack lever operated by the castlewheel, a spiral spring tor the operation ot the fly-back level', an intermediate lever ope-ated by the Castle-wheel, a spi *al spring` for the said internediate lever, an intermediate chronograph-wheel carried by the intermediate level', a center chronographwheel for co-action with the intermediate chronograph-wheel, and a star-cani nounted upon the sanie shaft as the center chi-onograph-wheel and acted upon by the fly-back leVer.

In testinony whereot, I have signed this specification in the presence ot two subscribing witnesses.

EDlVIN HART.

Witnesses CHARLES SCHMIDT, J. A. HUDNER.

Copies of this patent may be obtained for five cents each, by addressing the Commssioner of Patents, Washington, D. C. 

